Question

Four students, (A), (B), (C) and (D) observed the colour and solubility of Iron, Sulphur and Iron Sulphide in Carbon Disulphide. The tick mark (✔) represents 'soluble', and the cross mark (✕) represents 'insoluble', in Carbon Disulphide. Their observations are tabulated below.

Student	Colour			Solubility in Carbon Disulphide (${\mathbf{CS}}_{\mathbf{2}}$)
	$\mathbf{Fe}$	$\mathbf{S}$	$\mathbf{FeS}$	$\mathbf{Fe}$	$\mathbf{S}$	$\mathbf{FeS}$
(A)	Yellow	Silvery	Greyish silver	(✔)	(✕)	(✔)
	Silvery	Orange	Reddish-brown	(✕)	(✔)	(✔)
(B)
(C)	Grey	Yellow	Greyish black	(✕)	(✔)	(✕)
(D)	Silvery	White	Silvery white	(✔)	(✕)	(✕)

• A. (A)
• B. (B)
• C. (C)
• D. (D)

Answer 1

The correct option is C

(C)

The explanation of the correct answer.

Option C:

• Iron is grey in colour and Sulphur is yellow in colour.
• When Iron and Sulphur react they will form Iron Sulphide ($\mathbf{FeS}$) which is greyish black in colour.
• Sulphur is only soluble in ${\mathbf{CS}}_{\mathbf{2}}$ solution.

Hence, option (C) is correct.